Revert "add mibbit.com link to connect to #hubot-irc channel"
Revert "add mibbit.com link to connect to #hubot-irc channel"

Sad freenode does not support mibbit.com.  This reverts commit 04ec0b5f2587fba0f8d06801e9b8eebe23382d0a.

nandub/hubot-irc,miyazakijunichi/hubot-irc,miyazakijunichi/hubot-irc,nandub/hubot-irc,Spice-King/hubot-irc,BenoitZugmeyer/hubot-irc,BenoitZugmeyer/hubot-irc,Jaglag/hubot-irc,Jaglag/hubot-irc,Spice-King/hubot-irc